Field of the Invention
The present invention relates to a rotary machine, a blade wheel used in a rotary machine, and a blade wheel manufacturing method.
Description of the Related Art
Hitherto, a rotary machine with a rotatable blade wheel is known, and JP 2001-317492 A discloses a centrifugal compressor as an example of the rotary machine. The centrifugal compressor includes a casing and an impeller that corresponds to a blade wheel rotatably provided inside the casing.
The casing includes a tapered inner peripheral surface that increases in diameter as it goes from one end of the impeller in the axial direction toward the other end thereof. The impeller includes a plurality of blades that extend toward the inner peripheral surface of the casing, and each blade includes an outer edge that faces the inner peripheral surface of the casing.
In the inner peripheral surface of the casing, a portion on the upstream side (air flow suction side) is coated with a soft resin. Accordingly, even when the impeller rotates while being deviated in the radial direction, only the resin coating is cut by the blade of the impeller, so that the contact between the blade and the inner peripheral surface of the casing is prevented.